Device for simultaneously controlling a set of variable resistors

ABSTRACT

A device for controlling a set of variable resistors comprises a casing having a top wall, a bottom wall and a peripheral wall, a plurality of resistive bodies provided on top of the bottom wall of the casing, a rotatable guide member extending within the casing and positioned above and parallel with the individual resistive bodies, said rotatable guide member having the same number of guide arms as the number of the resistive bodies, a plurality of sliders each slidably mounted on the respective guide arms of the guide member and provided with respective brushes providing electric connection between the associated resistive bodies and a conductive portion of the guide member, an operable member having grooves receiving respective projections of the individual sliders, and a drive means for driving the operable member. The individual resistive bodies may belong to respective channels of a multi-channel system, and they may be separately controlled by operating a single operable shaft. Also, the level of output voltage from these resistive bodies may be simultaneously controlled by operating the shaft in a different way. Thus, two different control functions for controlling the same resistive bodies in different ways are provided.

Nishioka et a1.

Jan. 7, 1975 DEVICE FOR SIMULTANEOUSLY CONTROLLING A SET OF VARIABLERESISTORS Inventors: Matsuo Nishioka; Shunzo Oka, both of l-Iirakata,Japan Matsushita Electric Industrial Co., Ltd., Kadoma-shi, Osaka, JapanFiled: Apr. 8, 1974 Appl. N0.: 459,045

Assignee:

Foreign Application Priority Data Apr. 9, 1973 Japan 48-41049 Apr. 9,1973 Japan 48-43388 Apr. 9, 1973 Japan t l 48-43389 Apr. 9, 1973 Japan48-43390 References Cited UNITED STATES PATENTS Primary ExaminerBruce A.Reynolds Attorney, Agent, or FirmStevens, Davis, Miller & Mosher [57]ABSTRACT A device for controlling a set of variable resistors comprisesa casing having a top wall, a bottom wall and a peripheral wall, aplurality of resistive bodies provided on top of the bottom wall of thecasing, a rotatable guide member extending within the casing andpositioned above and parallel with the individual resistive bodies, saidrotatable guide member having the same number of guide arms as thenumber of the resistive bodies, a plurality of sliders each slidablymounted on the respective guide arms of the guide member and providedwith respective brushes providing electric connection between theassociated resistive bodies and a conductive portion of the guidemember, an operable member having grooves receiving respectiveprojections of the individual sliders, and a drive means for driving theoperable member. The individual resistive bodies may belong torespective channels of a multi-channel system, and they may beseparately controlled by operating a single operable shaft. Also, thelevel of output voltage from these resistive bodies may besimultaneously controlled by operating the shaft in a different way.Thus, two different control functions for controlling the same resistivebodies in different ways are provided.

7 Claims, 11 Drawing Figures DEVICE FOR SIMULTANEOUSLY CONTROLLING A SETOF VARIABLE RESISTORS This invention relates to variable resistorcontrols and, more particularly, to a device for controlling a set ofvariable resistors.

An object of the invention is to provide a device for controlling a setof variable resistors separately by operating a single operable shaft inone way and also controlling the level of output voltage from theindividual variable resistors simultaneously by operating the same shaftin a different way, that is, a device having two different controlfunctions for controlling the same variable resistors in different ways.

The device for controlling a set of variable resistors comprises acasing having a top wall, a bottom wall and a peripheral wall, aplurality of resistive bodies provided on top of the bottom wall of saidcasing, a rotatable guide member extending within said casing andpositioned above and parallel with said resistive bodies, said rotatableguide member having the same number of guide arms as the number of saidresistive bodies, a plurality of sliders each slidably mounted on therespective guide arms of said guide member and provided with respectivebrushes providing electric conduction between the associated resistivebodies and a conductive portion of said guide member, said sliders beingprovided with respective projections, an operable member having groovesreceiving the respective projections of said sliders, and a drive shaftfor driving said operable member. With this construction, the pluralityof resistive bodies, which may belong to respective channels of amulti-channel system, can be separately controlled by operating theshaft in one way, for controlling balance for instance, while they canalso be simultaneously controlled for controlling their output voltagelevels by operating the shaft in a different way, for controlling volumefor instance. Thus, the variable resistor control device according tothe invention is very useful for four-channel stereophonic systems andother multi-channel systems.

The above and other objects, features and advantages of the inventionwill become more apparent from the following description taken inconjunction with the accompanying drawings, in which:

FIG. 1 is a sectional view showing a device embodying the invention;

FIG. 2 is a top view of the same device with metal case and operabledisc being omitted;

FIG. 3 is a bottom view of the operable disc member in the same device;

FIG. 4 is a side view partly in section, of the same operable discmember;

FIG. 5 is a fragmentary perspective view showing part of the samedevice;

FIG. 6 is a perspective view of a brush used in the same device;

FIG. 7 is a top view of a resistive body used in the same device; and

FIGS. 8A, 8B, 8C and 8D illustrate the operation of the same device.

An embodiment of the invention will now be described in connection withFIGS. 1 to 7.

In the Figures, reference numeral 1 designates a metal case consistingof a top wall and a peripheral wall. Its top wall is formed with acentral aperture or window 2. A base 3 of an insulating material issecured to the case 1 at the bottom opening thereof by corkingprotuberances 4 thereof. Four sector-shaped resistive bodies 5a, 5b, Scand 5d are provided on the inner side of the base 3. They are arrangedto form a circle as a whole and are suitably spaced from one another.They are secured to the base by terminals 6a, 6a, 6b, 6b, 6c, 60', 6dand 6d, which are electrically connected to external circuitry. Numeral7 designates insulating spacers intervening between adjacent resistivebodies, and these insulating spacers 7 are constituted by a part of thebase 3. The resistive bodies 5a, 5b, 5c and 5d are provided withrespective silver terminal sections 811,812, and 8a, which are joined tothe respective terminals 6a, 6b, 6c and 6d. Extending above and parallelto the resistive bodies 5a, 5b, 5c and 5d is a cross shaped guide member9, which is rotatably supported on a support 10 extending upright fromthe center of the base 3. The guide member 9 consists of four guide arms9a, 9b, 9c and 9d, which are provided at their free end with respectivestoppers 11a, 11b, 11c and 11d in contact with and slidable over the topof a peripheral raised portion 3a of the base 3. The base 3 also hasstopper portions 12a and 12b raised from the peripheral raised portion3a. These stopper portions 12a and 12b serve to restrict the rotation ofthe guide member 9, and they are located on extensions of the oppositeedges of the sectorshaped resistive body 5a to subtend substantially thesame angle as the resistive body 5a. The rotation of the guide member 9is thus restricted as the stopper lla provided on the guide arm 9astrikes the stopper portions 12a and 12b. The guide member 9 is adaptedsuch that the guide arm 9a can rotate only over the resistive body 5a,the guide arm 912 only over the resistive body 5b, the guide arm 96 onlyover the resistive body 50 and the guide arm 9d only over the resistivebody 5d.

The guide member 9, or at least one surface thereof, is made of aconductive material, and its individual guide arms 9a, 9b, 9c and 9dcarry respective sliders 13a, 13b, 13c and 13d slidably mounted such asto surround the conductive material surface. These'sliders 13a to 13dare slidable between the aforesaid stoppers lla to 11d and a circularcentral portion 9e of the guide member 9. The sliders 13a, 13b, 13c and13d are provided with respective brushes 14a, 14b, 14c and 14d. whichhave one end in contact with the conductive portion of the guide member9 and the other end in contact with the associated one of the resistivebodies 5a, 511,50 and 5d. A conductive spring 15 is inserted between theconductive side of the guide member 9 and the support 10 on which theguide member 9 is also mounted, thus providing for electric connectionbetween the conductive portion of the guide member 9 and the support 10.Also, a spring 16 is fitted on the periphery of a portion of the support10 extending on the lower side of the base 3 opposite the guide member9, thus biasing the guide member 9 toward the base 3 to give adequatepressure on the brushes 14a, 14b, 14c and 14a. The support 10 isprovided with a retainer ring 17 for preventing the departure of thespring 16 from it. A terminal member 18 is provided between the base 3and the spring 16 such that it is electrically connected through thesupport 10 and a conductive portion of the guide member 9 to theaforesaid brushes 14a, 14b, 14c and 14d.

The sliders 13a, 13b, 13c and 13d have respective integral ornon-integral upper projections 19a, 19b, 19c and 1911. These projections19a, 19b, 19c and 19d are received in respective elongated grooves 21a,21b, 21c and 21d, which are formed on the inner side of a disc member 20provided within the case 1. The elongated grooves 21a to 21d arearranged such that they constitute respective four sides of a square.The disc member 20 has an operable shaft 22 extending upright from itstop and penetrating the aperture 2 formed in the case 1. By operatingthe shaft 22 sliding movement of the sliders 13a to 13d along therespective guide arms 9a to 9d can be caused.

The operation of the above construction will now be described. By movingthe operable shaft 22, and hence the disc member 20, in perpendiculardirections the sliders 13a, 13b, 13c and 13d, whose projections 19a,19b, 19c and 19d are received in the grooves 21a, 21b, 21c and 21dformed on the inner side of the disc member 20 and arranged in the formof a square, may move along the guide arms 9a, 9b, 9c and 9d. Forexample, by moving the operable shaft 22 in the directions of arrows A-Cin FIG. 2, the sliders 13a and 130 can be moved along the respectiveguide arms 9a and 90. Also, by moving the operable shaft 22 in thedirections of arrows D-B, the sliders 13b and 13d can be moved along theguide arms 9b and 9d. With the movement of the sliders 13a to 13d alongthe respective guide arms 9a to 9d the brushes 14a, 14b, 14c and 14d canbe moved over the respective resistive bodies 5a, 5b, 5c and 5d in theradial direction thereof.

On the other hand, by turning the operable shaft the guide arms 9a to 9dare rotated without sliding movement of the sliders 13a to 13d along theguide arms 9a to 9d, so that the brushes 14a to 14d can be moved overthe resistive bodies 5a to 5d in the circumferential direction thereof.7

Thus, it may be so arranged, for instance, that balance can be adjustedby moving the sliders 13a to 13d along the guide arms 9a to 9d whilevolume can be adjusted by rotating'the guide member 9 (Le, rotating thesliders 13a to 13d).

In this case, the brushes 14a to 14d are moved in the direction ofarrows XX in FIG. 7 (the radial direction of the resistive bodies 5a to5d), while they are moved in the direction of arrows Y-Y' (thecircumferential direction of the resistive bodies 5a to 5d) foradjusting the volume.

FIGS. 8A, 8B and 8C show output voltages for individual channelscorresponding to the respective resistive bodies as typically shown inFIG. 8D. FIG. 8A represents a case with the operable shaft 22 assumingthe central position of the device, FIG. 88 represents a case with theoperable shaft assuming a left position in FIG. 2, and FIG. 8Crepresents a case with the operable shaft assuming an upper leftposition in FIG. 2 (see FIG. 8D which illustrates the operatingpositions of the respective resistive bodies and the positions of therespective channels). In the individual cases, by turning the operableshaft 22 the individual channel voltages for balance as indicated bydots are varied along the associated dashed lines. Here, input voltagesappear between terminals 6a and 6a, between terminals 6b and 6b, betweenterminals 60 and 6c and between terminals 6d and 6d, and voltagesbetween terminals 14a and 6a, between terminals 14b and 6b, betweenterminals 14c and 6c and between terminals 14d and 6d are taken out asoutput voltage.

While in the above embodiment four resistive bodies are provided, thisis by no means limitative, but it is possible to provide any desirednumber of resistive bodies.

What we claim is:

l. A device for controlling a set of variable resistors comprising acasing having a top wall, a bottom wall and a peripheral wall, aplurality of resistive bodies provided on top of the bottom wall of saidcasing, a rotatable guide member extending within said casing andpositioned above and parallel with said resistive bodies, saidrotatable. guide having the same number of guide arms as the number ofsaid resistive bodies, a plurality of sliders each slidably mounted onthe respective guide arms of said guide member and provided withrespective brushes providing electric conduction between the associatedresistive bodies and a conductive portion of said guide member, saidsliders being provided with respective projections, an operable memberhaving grooves receiving the respective projections of said sliders, anda drive means for driving said operable member.

2. The device for controlling a set of variable resistors according toclaim 1, said guide members having Stoppers for restricting the slidablerange of said sliders, said stoppers being provided at the free ends ofthe respective guide arms, the bottom wall of said casing having raisedstopper portions adapted to engage with some of said stoppers forrestricting the rotation of said guide member.

3. The device for controlling a set of variable resistors according toclaim 1, wherein four sector-shaped resistive bodies are provided on topof the bottom wall of said casing and arranged at a suitable spacingfrom one another to form a circle, said guide member having four armsand being cross-shaped, said grooves formed in said operable memberbeing arranged to form a square.

4. The device for controlling a set ofvariable resistors accordingto-claim 1, wherein said casing comprises a metal case having a top walland a peripheral wall and a base of an insulating material, said basebeing secured to said case at the bottom opening thereof by corkingprotuberances of said case.

5. The device for controlling a set of variable resistors according toclaim 1, said casing having an aperture formed in the top wall, saiddrive means penetrating said aperture.

6. The device for controlling a set of variable resistors according toclaim 1, which further comprises a support extending upright from thebottom wall of said casing, said guide member being mounted on saidsupport, aconductive spring inserted between said support and theconductive portion of said guide member, and a spring provided on theperiphery of a portion of said support extending on the lower side ofsaid bottom wall of the casing opposite said guide member for biasingsaid guide member toward said bottom wall of the cas-- guide member.

1. A device for controlling a set of variable resistors comprising acasing having a top wall, a bottom wall and a peripheral wall, aplurality of resistive bodies provided on top of the bottom wall of saidcasing, a rotatable guide member extending within said casing andpositioned above and parallel with said resistive bodies, said rotatableguide having the same number of guide arms as the number of saidresistive bodies, a plurality of sliders each slidably mounted on therespective guide arms of said guide member and provided with respectivebrushes providing electric conduction between the associated resistivebodies and a conductive portion of said guide member, said sliders beingprovided with respective projections, an operable member having groovesreceiving the respective projections of said sliders, and a drive meansfor driving said operable member.
 2. The device for controlling a set ofvariable resistors according to claim 1, said guide members havingstoppers for restricting the slidable range of said sliders, saidstoppers being provided at the free ends of the respective guide arms,the bottom wall of said casing having raised stopper portions adapted toengage with some of said stoppers for restricting the rotation of saidguide member.
 3. The device for controlling a set of variable resistorsaccording to claim 1, wherein four sector-shaped resistive bodies areprovided on top of the bottom wall of said casing and arranged at asuitable spacing from one another to form a circle, said guide memberhaving four arms and being cross-shaped, said grooves formed in saidoperable member being arranged to form a square.
 4. The device forcontrolling a set of variable resistors according to claim 1, whereinsaid casing comprises a metal case having a top wall and a peripheralwall and a base of an insulating material, said base being secured tosaid case at the bottom opening thereof by corking protuberances of saidcase.
 5. The device for controlling a set of variable resistorsaccording to claim 1, said casing having an aperture formed in the topwall, said drive means penetrating said aperture.
 6. The device forcontrolling a set of variable resistors according to claim 1, whichfurther comprises a support extending upright from the bottom wall ofsaid casing, said guide member being mounted on said support, aconductive spring inserted between said support and the conductiveportion of said guide member, and a spring provided on the periphery ofa portion of said support extending on the lower side of said bottomwall of the casing opposite said guide member for biasing said guidemember toward said bottom Wall of the casing.
 7. The device forcontrolling a set of variable resistors according to claim 3, said guidemember having stoppers for restricting the slidable range of saidslider, said stoppers being provided at the free ends of the respectiveguide arms, the bottom wall of said casing having raised stopperportions adatped to engage with some of said stoppers for restrictingthe rotation of said guide member.